The stingray is a fascinating marine creature, categorized within the superorder Batoidea, a group of cartilaginous fish closely related to sharks. Their unique, flattened disc shape, formed by enlarged pectoral fins, allows them to glide gracefully through the water or bury themselves in the substrate. Stingrays are sometimes observed in groups, leading to the creation of specific terms to describe these aquatic gatherings.
Accepted Collective Terms
The most popular collective term for a group of stingrays is a “fever.” This term is associated with a large, dense aggregation of rays, sometimes involving thousands of individuals moving together. The unified movement of such a massive group likely inspired the unusual term.
A more general, but accurate, term is a “school” of stingrays, which applies to any large group of aquatic animals swimming in a coordinated manner. While some sources suggest “smack,” this term is more commonly designated for a group of jellyfish.
Biological Reasons for Grouping
Stingrays aggregate primarily due to biological imperatives rather than complex social bonds. One common driver for large-scale grouping is migration, evident in pelagic species like the Cownose ray. These rays form massive schools, cued by seasonal changes in water temperature, as they move between summer feeding grounds and warmer winter habitats. The southward migration of Cownose rays in the Atlantic can involve vast populations moving in unison.
Temporary, dense gatherings also form specifically for reproduction. Species such as the round stingray and the Atlantic stingray create seasonal mating aggregations. During these periods, males engage in courtship behaviors, which include biting the female’s pectoral fins to secure a grip for copulation. Aggregations can also occur for opportunistic feeding, such as when a highly concentrated food source, like a bed of clams or oysters, draws multiple individuals to the same small area.
Group Movement and Solitary Habits
For much of the year, many species of stingrays, particularly those that dwell on the bottom, are solitary. These benthic rays spend a significant amount of time resting, often partially buried in the sand or sediment to ambush prey or avoid detection. Their movement is typically slower and involves an undulatory motion of their pectoral fins.
The formation of a “fever” is a transient event, meaning the rays only remain together for the duration of the migration, mating, or feeding opportunity. When aggregated, the rays move with a coordinated purpose, especially in the shallow coastal waters or open ocean where these mass movements are most visible.
In contrast, pelagic species, such as eagle rays and manta rays, which spend little time on the seabed, have more pronounced grouping behaviors. These strong-swimming rays use an oscillatory movement, flapping their wing-like pectoral fins to cruise efficiently through the water column. This movement style facilitates the long-distance, deliberate migrations that characterize their life cycle. The temporary nature of their grouping underscores that for most species, the stingray’s primary existence is independent, with sociality reserved for specific life events.